<?php
/**
 * AKSRT Term Meta
 *
 * 为分类（category）和标签（post_tag）添加局部配置字段：
 * - 头图/封面 URL
 * - 自定义简介
 * - 列表布局模式覆盖
 * - 侧栏开关
 * - 推荐位开关
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Term_Meta {

    private static $instance = null;

    /** Supported taxonomies */
    private $taxonomies = ['category', 'post_tag'];

    /** Meta key for storing term-level settings */
    const META_KEY = AKSRT_Domain_Model::TERM_META_KEY;

    public static function get_instance(): self {
        if (null === self::$instance) self::$instance = new self();
        return self::$instance;
    }

    public function init(): void {
        // Register meta fields
        foreach ($this->taxonomies as $tax) {
            add_action("{$tax}_add_form_fields", [$this, 'render_add_fields']);
            add_action("{$tax}_edit_form_fields", [$this, 'render_edit_fields']);
            add_action("created_{$tax}", [$this, 'save_term_meta']);
            add_action("edited_{$tax}", [$this, 'save_term_meta']);
        }

        add_action('pre_get_posts', [$this, 'filter_archive_query']);
    }

    /**
     * Get term meta with defaults.
     */
    public static function get_meta(int $term_id): array {
        $defaults = AKSRT_Domain_Model::default_term_meta();
        $saved = get_term_meta($term_id, self::META_KEY, true);
        if (!is_array($saved)) $saved = [];
        return array_merge($defaults, $saved);
    }

    /**
     * Get a single term meta value.
     */
    public static function get_meta_value(int $term_id, string $key, $default = '') {
        $meta = self::get_meta($term_id);
        return $meta[$key] ?? $default;
    }

    /**
     * Resolve global page-display settings with term-level overrides.
     *
     * @param WP_Term $term Archive term.
     * @return array<string,mixed>
     */
    public static function resolve_archive_settings(WP_Term $term): array {
        $taxonomy = $term->taxonomy === 'post_tag' ? 'post_tag' : 'category';
        $global = $taxonomy === 'post_tag' && class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_tag_page_settings()
            : (class_exists('AKSRT_Settings') ? AKSRT_Settings::get_category_page_settings() : [
                'header_style'  => 'cover',
                'cover_enabled' => true,
                'desc_enabled'  => true,
                'list_mode'     => 'grid',
                'filter_bar'    => true,
                'sidebar'       => true,
                'per_page'      => 12,
            ]);

        $saved = get_term_meta($term->term_id, self::META_KEY, true);
        if (!is_array($saved)) {
            $saved = [];
        }

        $layout_mode = isset($saved['layout_mode']) && $saved['layout_mode'] !== ''
            ? sanitize_key((string) $saved['layout_mode'])
            : (string) ($global['list_mode'] ?? 'grid');

        $layout_map = [
            'grid'     => ['mode' => 'card', 'card_style' => 'standard'],
            'card'     => ['mode' => 'card', 'card_style' => 'standard'],
            'list'     => ['mode' => 'list', 'card_style' => 'standard'],
            'compact'  => ['mode' => 'list', 'card_style' => 'compact'],
            'mini'     => ['mode' => 'mini', 'card_style' => 'standard'],
            'grid-cms' => ['mode' => 'grid-cms', 'card_style' => 'standard'],
        ];
        $resolved_layout = $layout_map[$layout_mode] ?? ['mode' => 'card', 'card_style' => 'standard'];

        $header_style = (string) ($global['header_style'] ?? 'simple');
        if (!in_array($header_style, ['cover', 'simple', 'none'], true)) {
            $header_style = 'simple';
        }

        if (array_key_exists('show_header', $saved)) {
            $header_style = !empty($saved['show_header'])
                ? ($header_style === 'none' ? 'simple' : $header_style)
                : 'none';
        }

        $sidebar_enabled = (bool) ($global['sidebar'] ?? true);
        if (($saved['show_sidebar'] ?? '') === '1') {
            $sidebar_enabled = true;
        } elseif (($saved['show_sidebar'] ?? '') === '0') {
            $sidebar_enabled = false;
        }

        $cover_url = isset($saved['cover_url']) ? esc_url_raw((string) $saved['cover_url']) : '';
        if ($cover_url === '' && $taxonomy === 'category' && !empty($global['cover_enabled']) && class_exists('AKSRT_Settings')) {
            $cover_url = AKSRT_Settings::get_category_cover_url($term->term_id);
        }

        $description = isset($saved['description']) ? sanitize_textarea_field((string) $saved['description']) : '';
        if ($description === '') {
            $description = (string) $term->description;
        }

        return [
            'taxonomy'      => $taxonomy,
            'layout_mode'   => $resolved_layout['mode'],
            'card_style'    => $resolved_layout['card_style'],
            'layout_preset' => $layout_mode,
            'header_style'  => $header_style,
            'show_sidebar'  => $sidebar_enabled,
            'show_cover'    => $header_style === 'cover' && !empty($global['cover_enabled']) && $cover_url !== '',
            'show_desc'     => $taxonomy === 'post_tag' ? $description !== '' : (!empty($global['desc_enabled']) && $description !== ''),
            'filter_bar'    => $taxonomy === 'category' && !empty($global['filter_bar']),
            'per_page'      => max(4, min(48, (int) ($global['per_page'] ?? 12))),
            'cover_url'     => $cover_url,
            'description'   => $description,
        ];
    }

    /**
     * Apply archive per-page settings to the main query.
     */
    public function filter_archive_query(WP_Query $query): void {
        if (is_admin() || !$query->is_main_query()) {
            return;
        }

        $term = null;
        if ($query->is_category()) {
            $cat_id = absint($query->get('cat'));
            if ($cat_id > 0) {
                $term = get_term($cat_id, 'category');
            } else {
                $slug = sanitize_title((string) $query->get('category_name'));
                if ($slug !== '') {
                    $term = get_term_by('slug', $slug, 'category');
                }
            }
        } elseif ($query->is_tag()) {
            $tag_id = absint($query->get('tag_id'));
            if ($tag_id > 0) {
                $term = get_term($tag_id, 'post_tag');
            } else {
                $slug = sanitize_title((string) $query->get('tag'));
                if ($slug !== '') {
                    $term = get_term_by('slug', $slug, 'post_tag');
                }
            }
        }

        if (!$term instanceof WP_Term) {
            return;
        }

        $settings = self::resolve_archive_settings($term);
        if (!empty($settings['per_page'])) {
            $query->set('posts_per_page', (int) $settings['per_page']);
        }
    }

    /**
     * Render fields for "Add new term" form.
     */
    public function render_add_fields(string $taxonomy): void {
        ?>
        <div class="form-field">
            <label for="aksrt_term_cover_url"><?php esc_html_e('封面图 URL', 'aksrt'); ?></label>
            <input type="url" name="aksrt_term_meta[cover_url]" id="aksrt_term_cover_url" value="" placeholder="https://...">
            <p class="description"><?php esc_html_e('分类/标签页顶部封面图，留空则不显示。', 'aksrt'); ?></p>
        </div>
        <div class="form-field">
            <label for="aksrt_term_layout"><?php esc_html_e('列表布局', 'aksrt'); ?></label>
            <select name="aksrt_term_meta[layout_mode]" id="aksrt_term_layout">
                <option value=""><?php esc_html_e('跟随全局设置', 'aksrt'); ?></option>
                <option value="card"><?php esc_html_e('卡片模式', 'aksrt'); ?></option>
                <option value="list"><?php esc_html_e('列表模式', 'aksrt'); ?></option>
                <option value="mini"><?php esc_html_e('迷你模式', 'aksrt'); ?></option>
            </select>
        </div>
        <?php
    }

    /**
     * Render fields for "Edit term" form.
     */
    public function render_edit_fields(WP_Term $term): void {
        $meta = self::get_meta($term->term_id);
        ?>
        <tr class="form-field">
            <th scope="row"><label for="aksrt_term_cover_url"><?php esc_html_e('封面图 URL', 'aksrt'); ?></label></th>
            <td>
                <input type="url" name="aksrt_term_meta[cover_url]" id="aksrt_term_cover_url" value="<?php echo esc_url($meta['cover_url']); ?>" class="regular-text" placeholder="https://...">
                <p class="description"><?php esc_html_e('分类/标签页顶部封面图，留空则不显示。', 'aksrt'); ?></p>
            </td>
        </tr>
        <tr class="form-field">
            <th scope="row"><label for="aksrt_term_desc"><?php esc_html_e('自定义简介', 'aksrt'); ?></label></th>
            <td>
                <textarea name="aksrt_term_meta[description]" id="aksrt_term_desc" rows="3" class="large-text"><?php echo esc_textarea($meta['description']); ?></textarea>
                <p class="description"><?php esc_html_e('覆盖默认的分类/标签描述。', 'aksrt'); ?></p>
            </td>
        </tr>
        <tr class="form-field">
            <th scope="row"><label for="aksrt_term_layout"><?php esc_html_e('列表布局', 'aksrt'); ?></label></th>
            <td>
                <select name="aksrt_term_meta[layout_mode]" id="aksrt_term_layout">
                    <option value="" <?php selected($meta['layout_mode'], ''); ?>><?php esc_html_e('跟随全局设置', 'aksrt'); ?></option>
                    <option value="card" <?php selected($meta['layout_mode'], 'card'); ?>><?php esc_html_e('卡片模式', 'aksrt'); ?></option>
                    <option value="list" <?php selected($meta['layout_mode'], 'list'); ?>><?php esc_html_e('列表模式', 'aksrt'); ?></option>
                    <option value="mini" <?php selected($meta['layout_mode'], 'mini'); ?>><?php esc_html_e('迷你模式', 'aksrt'); ?></option>
                </select>
            </td>
        </tr>
        <tr class="form-field">
            <th scope="row"><?php esc_html_e('显示设置', 'aksrt'); ?></th>
            <td>
                <label>
                    <input type="checkbox" name="aksrt_term_meta[show_header]" value="1" <?php checked(!empty($meta['show_header'])); ?>>
                    <?php esc_html_e('显示页面头部（标题、描述）', 'aksrt'); ?>
                </label><br>
                <label>
                    <input type="checkbox" name="aksrt_term_meta[show_sidebar]" value="1" <?php checked($meta['show_sidebar'] === '1'); ?>>
                    <?php esc_html_e('强制显示侧栏', 'aksrt'); ?>
                </label><br>
                <label>
                    <input type="checkbox" name="aksrt_term_meta[show_featured]" value="1" <?php checked(!empty($meta['show_featured'])); ?>>
                    <?php esc_html_e('显示推荐文章位', 'aksrt'); ?>
                </label>
            </td>
        </tr>
        <?php
    }

    /**
     * Save term meta from form submission.
     */
    public function save_term_meta(int $term_id): void {
        if (!isset($_POST['aksrt_term_meta']) || !is_array($_POST['aksrt_term_meta'])) {
            return;
        }
        if (!current_user_can('manage_categories')) {
            return;
        }

        $raw = $_POST['aksrt_term_meta'];
        $sanitized = [
            'cover_url'    => isset($raw['cover_url']) ? esc_url_raw($raw['cover_url']) : '',
            'description'  => isset($raw['description']) ? sanitize_textarea_field($raw['description']) : '',
            'layout_mode'  => isset($raw['layout_mode']) ? sanitize_key($raw['layout_mode']) : '',
            'show_sidebar' => isset($raw['show_sidebar']) ? '1' : '',
            'show_header'  => isset($raw['show_header']) ? true : false,
            'show_featured' => isset($raw['show_featured']) ? true : false,
        ];

        // Only allow valid layout modes
        $valid_modes = ['', 'card', 'list', 'mini', 'grid-cms'];
        if (!in_array($sanitized['layout_mode'], $valid_modes, true)) {
            $sanitized['layout_mode'] = '';
        }

        update_term_meta($term_id, self::META_KEY, $sanitized);
    }
}